I am working adding a narrow gauge line to my O Gauge layout. Given my limited space while I can cross some of the track by creating a viaduct for it to cross once I will need to have a grade level crossing at some point as there will not be sufficient space to go up and come down without it.

I am guessing that there are no commercially available such crossings so I am going to need to try and build my own. I'd love to hear from anyone else who has attempted this as it will be a first time trying something like this for me. Pictures would be great.

A simple answer is to buy an O scale crossing. First cut out in the middle of one track for the On30 a piece with minimum 0.610 inch = 15,5 mm wide.You must cut parallel to the future On30 rails the sleepers and the two O gauge rails.Connect the both cut rails for O gauge track with rail joiners.Then glue the booth connected parts on a base plate together. Use an NMRA HO track gauge or better make three .650 inch = 16,5 mm width strips from cardboard for measuring and hold the exact On30 track width while gluing.Be sure that the both tracks are isolated to another or isolate the complete crossing and switch the power for use On30 track or O track.

Thanks, I think the basic idea will work but my O system is three rail so I'll need to figure out a few things. I am thinking of omitting the power rail at the point of the junction, I know that will be no problem as many stock three rail crossings use a model plastic area at the junction and the loco pickups will easily bridge the gap and keep moving. I am not sure how the pickups work on my On30 locos, I realize the power travels through the wheels but I am not sure if all wheels are involved. I'll need to check that as ideally I'd like the On30 rails not to carry power at the junction as the pick roller from the O will contact them and could short the the two systems together. I thought about cutting them to allow a path but the gap would be to long without rail for the On30 loco to safely cross. A particular problem since On30 will be DCC and my three rail is the classic AC system.

If any one has tried this and has pictures they would be greatly appreciated.

Trying to combine DCC with three-rail AC courts disaster. It would seem to me that you would need to totally isolate the entire crossing electrically and use a DPDT center-off switch to choose either the AC side or the DCC side.

All too true. I have a couple of ideas of how to achieve isolation of the two circuits, but I need to figure out just how much of the wheel base on my primary On30 has to be in contact with power for the loco to run. The the issue will be lining up the rails properly and close enough on height that it doesn't lead to an endless series of derailments.